LaKSA: A Probabilistic Proof-of-Stake Protocol

TL;DR

LaKSA is a scalable, lightweight Proof-of-Stake protocol that enhances security and efficiency through committee voting, probabilistic safety guarantees, and broad applicability to large blockchain networks.

Contribution

Introduces LaKSA, a novel chain-based PoS protocol with lightweight voting, probabilistic safety, and broad scalability, improving robustness and reducing confirmation times.

Findings

Supports large-scale networks with many nodes

Provides probabilistic safety guarantees for transactions

Demonstrates improved scalability and robustness

Abstract

We present Large-scale Known-committee Stake-based Agreement (LaKSA), a chain-based Proof-of-Stake protocol that is dedicated, but not limited, to cryptocurrencies. LaKSA minimizes interactions between nodes through lightweight committee voting, resulting in a simpler, more robust, and more scalable proposal than competing systems. It also mitigates other drawbacks of previous systems, such as high reward variance and long confirmation times. LaKSA can support large numbers of nodes by design, and provides probabilistic safety guarantees in which a client makes commit decisions by calculating the probability that a transaction is reverted based on its blockchain view. We present a thorough analysis of LaKSA and report on its implementation and evaluation. Furthermore, our new technique of proving safety can be applied more broadly to other Proof-of-Stake protocols.